1. Field of the Invention
The present invention generally relates to a method that reduces the use of critical masks by using a blockout mask. As a result, a unique semiconductor structure can be formed.
2. Description of the Related Art
Microelectronic circuit fabrication requires application of a series of photolithography masking steps for patterning of device structures. In advanced DRAM and logic circuits, fabrication process complexity can require more than one critical mask per level. Minimization of critical masks is critical for fabrication cost control. The present invention reduces the number of critical masks through introduction of a blockout mask. With this method, DRAM array and support contact holes can be formed in the same etching step. Similarly, logic gate conductors may be formed in the same step and later doped for a desired work function.